A submarine-like vessel carrying more than eight tonnes of cocaine has been seized by US authorities off the coast of El Salvador.

Authorities found 274 bales containing 7,650kg of cocaine worth hundreds of millions of dollars on the semi-submersible vessel after it was intercepted on Saturday.

Warnings of the use of submarines by drug traffickers go back as far as 2010, when Royal Navy officers said they were increasingly being used to transport the illicit cargo from Latin America to Europe and Britain.

Wealthy crime cartels were said to be using the underwater craft in a bid to avoid the rising number of naval patrols in the Caribbean.

In the incident on Saturday, US aircraft tracked the vessel as it made its way through international waters off the El Salvador coast, before it was intercepted by the Coast Guard, the Associated Press reported.

Four suspected smugglers were taken into custody after the vessel was stopped.

Last month Spanish police seized 200kg of cocaine found in hollowed-out pineapples on a ship from Central America.

The fruit was among ten containers which arrived in the port of Algeciras, the Spanish interior ministry said.